Magnetic memory construction



June 28, 1955 M. RosENBERG Er AL MAGNETIC MEMORY CONSTRUCTION Filed Aug. 9, 1954 NVENTORS PNG United States Patent O MAGNETIC MEMORY CONSTRUCTION Milton Rosenberg, Santa Monica, and Benedict Stanavige, Duarte, Calif., assignors to International Telemeter Corporation, Los Angeles, Calif., a corporation of Delaware Application August 9, 1954, Serial No. 448,606

9 Claims. (Cl. 340-166) This invention relates to magnetic-core memories and, more particularly, to an improved structure for a magnetic-core memory.

A structure for a magnetic-core memory array has been shown and described, for example, in an article by Dr. Jan A. Rajchman, in the Proceedings of the IRE, October 1953, entitled A Myriabit magnetic-core matrix memory.

In an application by Raymond Stuart-Williams et al. for a Magnetic-Core Memory System, Serial Number 421,142, led April 5, 1954, the advantage of employing a folded column is described. This folded-column construction is also described and claimed in an application by Raymond Stuart-Williams et al. for a Magnetic Memory Device, Serial Number 448,603, led August 9, 1954. Both of these applications are assigned to this assignee.

In the construction of a magnetic memory core plane heretofore, a framework consisting essentially of a rectangular frame of some nonmagnetic and nonconducting material such as Bakelite or mica mold has terminals attached thereto on the framework. The wires which are used for coils coupling columns and rows of cores are stretched and connected between these terminals, and the cores are supported by these wires. The Rajchman article shows a photograph of an array of this sort. In constructing a folded-column memory, the rectangular framework was retained as well as the terminals on the frame. Two members which may be called bridge members are mounted inside the frame and near the ends thereof. Column coils are wound to pass over these bridge members. The column coil for a folded column is one which has cores coupled to both sides of a coil. This effect is achievable since the cores in a column are essentially divided in half with one-half of the cores being positioned adjacent the other half. The turn of a column coil is taken up through one-half of the cores and down through the other half of the cores. VIf a bridge member is inserted at the ends of the coil where they turn to go through half of the cores in the column, then the means for supporting column coils as briefly described above may be visualized readily. With an increase in the desired size of the memory planes, the material of which the frames are fabricated is put under stress by reason of the wire used to form the coils, and thus a rather fragile memory plane is formed.

An object of the present invention is to provide a memory plane having a mechanically substantial construction. In applying current drives to a coil employed in a memory, a very important consideration is the minimization of the inductance seen by the current drive. It has been found that two main contributions exist to the inductance of a row or a column coil. One is the air inductance of the winding itself and the second is the contribution to the inductance of the cores which are included in a winding.

A further object of the present invention is to minimize the inductance provided through the air.

Patented June 28, 1955 ICC Another consideration in the construtcion of a core memory is a minimization of the D. C. resistance of row coils.

Still a further object of the invention is to provide a ylow D. C. resistance and convenient mechanical return path for these drives.

Yet another object of the present invention is the provision of a magnetic memory core plane structure which enables simple and rapid assembly of a folded-column memory plane.

These and other objects of the invention are achieved in the provision of a core memory plane wherein a ground plane made of a flat, substantially nonmagnetic and conducting plane is employed, and the framework upon which the terminals are mounted are all supported by means of this ground plane. The column coils are wound so that the turns of each coil in passing through the cores also enclose the ground plane. The ground plane serves as a return path for the row coils.

The novel features that are considered characteristic of this invention are set forth with particularity in the appended claims. The invention, itself, both as to its organization and method of operation, as well as additional objects and advantages thereof, will best be understood from the following description when read in connection with the accompanying drawings, in which:

Figure 1 is a plan view of the structure for a magneticcore memory array;

Figure 2 is a view in section along the line 2--2 of the drawing in Figure 1;

Figure 3 is a view in section along the line 3-3 of the drawing shown in Figure 1; and

Figure 4 is a perspective view of a magnetic core showing the manner in which the coils of the core plane pass through a core.

Referring now to Figure 1, the structure for the core plane consists of a ground plane 10 which is made of a sheet of nonmagnetic conducting material, such as brass. It is upon this ground plane that the entire framework of the memory is constructed. As is seen in Figure 2, the ground plane has angles 12 welded thereto so that effectively an I-beam structure is secured. At the lower side of the ground plane there is attached thereto, as shown in Figure 2, a at member 14 made of insulating material such as Bakelite and the like. This flat member can consist of a single piece of Bakelite which has a groove cut in one lside to enable its beir'ig fitted to the ground plane up unto the angles. If desired, this at member 14 may be made from two llat members which sandwich one end of the ground plane between them. The llat member is located with respect to the ground plane by means of pins 16.

A pair of nonmagnetic conducting metal strips 18 such as brass have spaced terminals 20 attached thereto. The spacing of these terminals may better be seen in Figure l. These metal strips are used to sandwich the at member 14 and are also held in place by the pins 16 so as to contact the angles 12. Thus, all the terminals 20 which extend on either side of the ground plane are also in electrical contact with it. A pair of bridge members 22 are mounted on either side of the plane abutting the angles and are also held in place by means of the pins 16. These are called bridge members, because as will be seen by regarding Figure l, the wires which form the row vcoils for the memory are stretched over the bridge members in much the same fashion as the string` members 26, 28. These serve to sandwich the ground plane which extends somewhat beyond the position of these two at members. These flat members are positioned to abut the angles 12. They are held in place on the ground plane by pins 30. Terminals 32 are mounted in these tlat members in a manner not to contact the ground plane. The spacing of these .terminals as shown in Figure l is made complementary to the terminals 20 so that the row coil can be stretched in a straight line between the terminals. Two more bridge members 34 are employed on either side of the ground plane which are also positioned abutting the angles 12 and are held in place by the pins 39. On the other extremities of the flat members there are mounted two other at members, respectively 36, 38. These are positioned so that there is a space between the ground plane and these two members. These two members also serve as mounting boards for spaced terminals 40, 42. In the space between these latter flat members and the edge of the ground plane, there are positioned two semicircular bridge members 44, 46. These may be formed from rod material which is nonrnagnetic and nonconducting and which has a groove notched in its ilat surface to permit the attachment to the ground plane.

Guiding grooves are cut in the outer surface of these semicircular bridge members.

As shown in Figure l, essentially what is provided is a sandwich consisting of two rectangular frames which eiectively serve as the terminal boards for the coils employed in a member. These rectangular planes enclose the ground plane. Bridge members are provided for holding .the wires used for coils in place. Any stress which is established as a result of the pull by the wires is sustained by the metal ground plane and not by tbe fragile framework structure employed previously'. Thus, a mechanically strong memory core plane construction is provided by this invention.

ln the assemblage of the cores on to the frame-Work heretofore, the Stringing of the wires through the cores was a tiresome, eyestraining process in that the core sizes are rather small and it was ditlicult oftentimes to distinguish the cores from the background. The bright metal finish of the metallic ground plane provides a background which makes the cores on the upper half of the folded column readily distinguishable from those on the lower half of the folded column and sets them out so well that the threading of the cores for a memory is considerablysimplitied and memory construction itself is considerably accelerated.

As may be seen from Figure l and Figure ll, a row coil 24 consists of a single turn which passes from a terminal 20 toa corresponding terminal 32 through a core 48. The folded-column construction requires that some of the cores in a column be adjacent to the remaining cores in a column instead of the cores in a column being in single le as heretofore. Thus, some of the cores 43 are on one side of the ground plane and other cores 48 exactly similarly disposed are on the opposite side of the ground plane, as may be seen in Figure 3. Accordingly, to wind a column coil, the number of turns desired in the coil pass through all the cores in a column at one side of the ground plane, then around a circular bridge member through the cores in the column on the other side of the ground plane, then back around the other circular bridge member through the same cycle for as many times as there are desired turns in a column coil 50. It will be appreciated, therefore, that cach of the column coils included the ground plane in their windings. The column coil starts from a terminal on one side of the flat member 38 and ends at a terminal on the other side of the ilat member 33. This can be seen more easily by regarding Figure 3.

A reading coil 52 .for the memory is provided by connecting from one of the terminals 40 mounted on the flat member 36 through the portion of the column lil of coils on the same side as the terminal back through the adjacent cores forming a portion of a column to the adjacent terminal. In this manner, reading coil windings through the entire memory are established and connections of the terminals on top and bottom of the member 36 may be made in any desired interlacing fashion for the reading coil. A plug and connector 54 is provided to permit takeoff of the reading voltages obtained. lt will be appreciated that one side of the row coils are connected to ground via the ground plane. Thus, a very loul D. C. resistance and return path for the coils is provided.

The air inductance of the coils is minimized by virtue of the ground plane. Also, any inductive effects created by the cores on one-half of the column through the air to the coil which links the other half of 'the column are minimized. A core memory of the type described here has been constructed for 4096 cores and has provided a mechanically solid and compact structure with a minimal inductance in the coils which are ernployed for driving the cores. lt will be appreciated that only a few coils are shown in order to prevent undue complication of the drawings. The size of the memory may be expanded to provide any desired number or" cores and thereby any desired number of binary digits can be remembered.

Accordingly, there has been shown and described hereinabove a novel, useful, and desirable construction for a magnetic-core memory plane.

We claim:

l. A magnetic memory core plane stlucture comprising a pair of rectangular frames made of nonrnagnetic and nonconducting material, a ground plane sandwiched between said two frames, said ground plane being madey of nonmagnetic conducting material, and a plurality of terminals mounted at spaced positions around said rectangular frames on the outer periphery and to extend outward from said ground plane, the terminals on one side of said frame being mounted to be in contact with said ground plane.

2. A magnetic memory core plane structure comprising a pair of rectangular frames made of nonmagnetic and nonconducting material, a ground plane made of nonmagnetic conducting material, said ground plane being sandwiched between said two frames, the length of said ground plane being sutliciently smaller than the inner length of one side of said pair of rectangular frames to provide a space on either side of said plane between said plane and two opposite sides of said rectangular frames, a pair of bridging members one mounted on either side of said ground plane in said spaces, and a plurality of terminals mounted at spaced positions around said rectangular frames on the outer periphery and to extend outward from said ground plane, the terminals on one side of said frame wherein said ground plane extends being mounted to be in contact with said ground plane.

3. A magnetic core memory plane structure comprising a hat substantially rectangular ground plane made of nonmagnetic conducting material, a rst at nonrnagnetie member, a plurality of terminals, means to attach said member to one side of said ground plane, means to mount said terminals at spaced positions in said tirst member and to contact said ground plane, second and third flat nonmagnetic members, a plurality of terminals mounted at spaced positions in said second and third members, means to attach said second and third members to opposite surfaces of said ground plane near the edge opposite to said one side, a rst pair of bridging members attached to said ground plane at said opposite edges adjacent said one side, second and third pairs of bridging members, and means to attach said second and third bridging members respectively to said rst and said second and third ilat members to be supported thereby alongside of said opposite edges adjacent said one side of said ground plane.

4. A magnetic core memory plane as recited in claim 3 wherein said means to attach said first lat member and said second and third flat members to said ground plane each includes an angle attached to said ground piane and against which said flat members abut.

5. A magnetic core memory plane structure comprising a substantially flat rectangular ground plane made of substantially nonmagnetic metal, a rst plurality of terminals` means attached to one side of said ground plane to support said first plurality of terminals in spaced relationship extending in equal number outwardly from on both sides of and in contact with said ground plane, a second plurality of terminals, means to support equal portions of said second plurality of terminals on both sides of and from near the side opposite said one side of said ground plane, third and fourth pluralities of terminals, and means to support said third and fourth pluralities of terminals respectively alongside of the opposite edges of said ground plane adjacent said one side.

6. A magnetic core memory plane structure compris ing a substantially at rectangular ground plane, a 'plurality of magnetic cores arranged in columns andrews, some of the cores in each column being on one side of said ground plane, the remainder of the cores in .each column being on the opposite side of said ground plane, and a plurality of column coils, each one of which is inductively coupled to all the cores in a different column, the turns of each of said column coils enclosing said ground plane.

7. A magnetic core memory plane structure comprising a substantially at rectangular ground plane, a plurality of magnetic cores arranged in columns and rows, some of the cores in each column being on one side of said ground plane, the remainder of the cores in each column being on the opposite side of said ground plane, a plurality of column coils each one of which is inductively coupled to all the cores in a different column, each of the turns of each of said column coils passing through all the cores of the column and enclosing said ground plane, a plurality of terminals to different pairs of which each of said column coils is connected, means to support said terminals at one side of and from said ground plane, a plurality of row coils each of which is inductively coupled to all the cores in a different row, a second and third plurality of terminals, and means to support said second and third plurality of terminals at opposite sides of said ground plane which are adjacent said one side, each of said row coils being connected to a dilerent one of said second and third plurality of terminals.

S. A magnetic core memory plane as recited in claim 7 wherein there is included a reading coil including a plurality of windings inductively coupled to all the cores in said columns and rows, a fourth plurality of terminals, means supporting said fourth plurality of terminals adjacent from the end of said ground plane opposite said one side, said plurality of windings being connected to said fourth plurality of terminals, and means interconnecting said fourth plurality of terminals to form a reading coil having a desired interlace pattern.

9. A magnetic core memory plane as recited in claim 7 wherein said means to support said second and third plurality of terminals includes means to connect said second plurality of terminals to said ground plane.

No references cited. 

